/*
 **********************************************************************
 ** md5.c                                                            **
 ** RSA Data Security, Inc. MD5 Message Digest Algorithm             **
 ** Created: 2/17/90 RLR                                             **
 ** Revised: 1/91 SRD,AJ,BSK,JT Reference C Version                  **
 **********************************************************************
 */

/*
 **********************************************************************
 ** Copyright (C) 1990, RSA Data Security, Inc. All rights reserved. **
 **                                                                  **
 ** License to copy and use this software is granted provided that   **
 ** it is identified as the "RSA Data Security, Inc. MD5 Message     **
 ** Digest Algorithm" in all material mentioning or referencing this **
 ** software or this function.                                       **
 **                                                                  **
 ** License is also granted to make and use derivative works         **
 ** provided that such works are identified as "derived from the RSA **
 ** Data Security, Inc. MD5 Message Digest Algorithm" in all         **
 ** material mentioning or referencing the derived work.             **
 **                                                                  **
 ** RSA Data Security, Inc. makes no representations concerning      **
 ** either the merchantability of this software or the suitability   **
 ** of this software for any particular purpose.  It is provided "as **
 ** is" without express or implied warranty of any kind.             **
 **                                                                  **
 ** These notices must be retained in any copies of any part of this **
 ** documentation and/or software.                                   **
 **********************************************************************
 */

#include <shim_internal.h>
#include <shim_utils.h>

/* forward declaration */
static void __transform(UINT4* buf, UINT4* in);

static unsigned char PADDING[64] = {
    0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};

/* F, G and H are basic MD5 functions: selection, majority, parity */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

/* ROTATE_LEFT rotates x left n bits */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32 - (n))))

/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4 */
/* Rotation is separate from addition to prevent recomputation */
#define FF(a, b, c, d, x, s, ac)                     \
    {                                                \
        (a) += F((b), (c), (d)) + (x) + (UINT4)(ac); \
        (a) = ROTATE_LEFT((a), (s));                 \
        (a) += (b);                                  \
    }
#define GG(a, b, c, d, x, s, ac)                     \
    {                                                \
        (a) += G((b), (c), (d)) + (x) + (UINT4)(ac); \
        (a) = ROTATE_LEFT((a), (s));                 \
        (a) += (b);                                  \
    }
#define HH(a, b, c, d, x, s, ac)                     \
    {                                                \
        (a) += H((b), (c), (d)) + (x) + (UINT4)(ac); \
        (a) = ROTATE_LEFT((a), (s));                 \
        (a) += (b);                                  \
    }
#define II(a, b, c, d, x, s, ac)                     \
    {                                                \
        (a) += I((b), (c), (d)) + (x) + (UINT4)(ac); \
        (a) = ROTATE_LEFT((a), (s));                 \
        (a) += (b);                                  \
    }

void md5_init(mdContext)
    struct shim_md5_ctx* mdContext;
{
    mdContext->i[0] = mdContext->i[1] = (UINT4)0;

    /* Load magic initialization constants.
     */
    mdContext->buf[0] = (UINT4)0x67452301;
    mdContext->buf[1] = (UINT4)0xefcdab89;
    mdContext->buf[2] = (UINT4)0x98badcfe;
    mdContext->buf[3] = (UINT4)0x10325476;
}
EXTERN_ALIAS(md5_init);

void md5_update(mdContext, inBuf, inLen)
    struct shim_md5_ctx* mdContext;
    const void* inBuf;
    size_t inLen;
{
    UINT4 in[16];
    int mdi;
    unsigned int i, ii;

    /* compute number of bytes mod 64 */
    mdi = (int)((mdContext->i[0] >> 3) & 0x3F);

    /* update number of bits */
    if ((mdContext->i[0] + ((UINT4)inLen << 3)) < mdContext->i[0])
        mdContext->i[1]++;
    mdContext->i[0] += ((UINT4)inLen << 3);
    mdContext->i[1] += ((UINT4)inLen >> 29);

    while (inLen--) {
        /* add new character to buffer, increment mdi */
        mdContext->in[mdi++] = *(unsigned char*)inBuf++;

        /* transform if necessary */
        if (mdi == 0x40) {
            for (i = 0, ii = 0; i < 16; i++, ii += 4)
                in[i] = (((UINT4)mdContext->in[ii + 3]) << 24) |
                        (((UINT4)mdContext->in[ii + 2]) << 16) |
                        (((UINT4)mdContext->in[ii + 1]) << 8) | ((UINT4)mdContext->in[ii]);
            __transform(mdContext->buf, in);
            mdi = 0;
        }
    }
}
EXTERN_ALIAS(md5_update);

void md5_final(mdContext)
    struct shim_md5_ctx* mdContext;
{
    UINT4 in[16];
    int mdi;
    unsigned int i, ii;
    unsigned int padLen;

    /* save number of bits */
    in[14] = mdContext->i[0];
    in[15] = mdContext->i[1];

    /* compute number of bytes mod 64 */
    mdi = (int)((mdContext->i[0] >> 3) & 0x3F);

    /* pad out to 56 mod 64 */
    padLen = (mdi < 56) ? (56 - mdi) : (120 - mdi);
    md5_update(mdContext, PADDING, padLen);

    /* append length in bits and transform */
    for (i = 0, ii = 0; i < 14; i++, ii += 4)
        in[i] = (((UINT4)mdContext->in[ii + 3]) << 24) | (((UINT4)mdContext->in[ii + 2]) << 16) |
                (((UINT4)mdContext->in[ii + 1]) << 8) | ((UINT4)mdContext->in[ii]);
    __transform(mdContext->buf, in);

    /* store buffer in digest */
    for (i = 0, ii = 0; i < 4; i++, ii += 4) {
        mdContext->digest[ii]     = (unsigned char)(mdContext->buf[i] & 0xFF);
        mdContext->digest[ii + 1] = (unsigned char)((mdContext->buf[i] >> 8) & 0xFF);
        mdContext->digest[ii + 2] = (unsigned char)((mdContext->buf[i] >> 16) & 0xFF);
        mdContext->digest[ii + 3] = (unsigned char)((mdContext->buf[i] >> 24) & 0xFF);
    }
}

/* Basic MD5 step. Transform buf based on in.
 */
static void __transform(buf, in)
    UINT4* buf;
    UINT4* in;
{
    UINT4 a = buf[0], b = buf[1], c = buf[2], d = buf[3];

    /* Round 1 */
#define S11 7
#define S12 12
#define S13 17
#define S14 22
    FF(a, b, c, d, in[0], S11, 3614090360);  /* 1 */
    FF(d, a, b, c, in[1], S12, 3905402710);  /* 2 */
    FF(c, d, a, b, in[2], S13, 606105819);   /* 3 */
    FF(b, c, d, a, in[3], S14, 3250441966);  /* 4 */
    FF(a, b, c, d, in[4], S11, 4118548399);  /* 5 */
    FF(d, a, b, c, in[5], S12, 1200080426);  /* 6 */
    FF(c, d, a, b, in[6], S13, 2821735955);  /* 7 */
    FF(b, c, d, a, in[7], S14, 4249261313);  /* 8 */
    FF(a, b, c, d, in[8], S11, 1770035416);  /* 9 */
    FF(d, a, b, c, in[9], S12, 2336552879);  /* 10 */
    FF(c, d, a, b, in[10], S13, 4294925233); /* 11 */
    FF(b, c, d, a, in[11], S14, 2304563134); /* 12 */
    FF(a, b, c, d, in[12], S11, 1804603682); /* 13 */
    FF(d, a, b, c, in[13], S12, 4254626195); /* 14 */
    FF(c, d, a, b, in[14], S13, 2792965006); /* 15 */
    FF(b, c, d, a, in[15], S14, 1236535329); /* 16 */

    /* Round 2 */
#define S21 5
#define S22 9
#define S23 14
#define S24 20
    GG(a, b, c, d, in[1], S21, 4129170786);  /* 17 */
    GG(d, a, b, c, in[6], S22, 3225465664);  /* 18 */
    GG(c, d, a, b, in[11], S23, 643717713);  /* 19 */
    GG(b, c, d, a, in[0], S24, 3921069994);  /* 20 */
    GG(a, b, c, d, in[5], S21, 3593408605);  /* 21 */
    GG(d, a, b, c, in[10], S22, 38016083);   /* 22 */
    GG(c, d, a, b, in[15], S23, 3634488961); /* 23 */
    GG(b, c, d, a, in[4], S24, 3889429448);  /* 24 */
    GG(a, b, c, d, in[9], S21, 568446438);   /* 25 */
    GG(d, a, b, c, in[14], S22, 3275163606); /* 26 */
    GG(c, d, a, b, in[3], S23, 4107603335);  /* 27 */
    GG(b, c, d, a, in[8], S24, 1163531501);  /* 28 */
    GG(a, b, c, d, in[13], S21, 2850285829); /* 29 */
    GG(d, a, b, c, in[2], S22, 4243563512);  /* 30 */
    GG(c, d, a, b, in[7], S23, 1735328473);  /* 31 */
    GG(b, c, d, a, in[12], S24, 2368359562); /* 32 */

    /* Round 3 */
#define S31 4
#define S32 11
#define S33 16
#define S34 23
    HH(a, b, c, d, in[5], S31, 4294588738);  /* 33 */
    HH(d, a, b, c, in[8], S32, 2272392833);  /* 34 */
    HH(c, d, a, b, in[11], S33, 1839030562); /* 35 */
    HH(b, c, d, a, in[14], S34, 4259657740); /* 36 */
    HH(a, b, c, d, in[1], S31, 2763975236);  /* 37 */
    HH(d, a, b, c, in[4], S32, 1272893353);  /* 38 */
    HH(c, d, a, b, in[7], S33, 4139469664);  /* 39 */
    HH(b, c, d, a, in[10], S34, 3200236656); /* 40 */
    HH(a, b, c, d, in[13], S31, 681279174);  /* 41 */
    HH(d, a, b, c, in[0], S32, 3936430074);  /* 42 */
    HH(c, d, a, b, in[3], S33, 3572445317);  /* 43 */
    HH(b, c, d, a, in[6], S34, 76029189);    /* 44 */
    HH(a, b, c, d, in[9], S31, 3654602809);  /* 45 */
    HH(d, a, b, c, in[12], S32, 3873151461); /* 46 */
    HH(c, d, a, b, in[15], S33, 530742520);  /* 47 */
    HH(b, c, d, a, in[2], S34, 3299628645);  /* 48 */

    /* Round 4 */
#define S41 6
#define S42 10
#define S43 15
#define S44 21
    II(a, b, c, d, in[0], S41, 4096336452);  /* 49 */
    II(d, a, b, c, in[7], S42, 1126891415);  /* 50 */
    II(c, d, a, b, in[14], S43, 2878612391); /* 51 */
    II(b, c, d, a, in[5], S44, 4237533241);  /* 52 */
    II(a, b, c, d, in[12], S41, 1700485571); /* 53 */
    II(d, a, b, c, in[3], S42, 2399980690);  /* 54 */
    II(c, d, a, b, in[10], S43, 4293915773); /* 55 */
    II(b, c, d, a, in[1], S44, 2240044497);  /* 56 */
    II(a, b, c, d, in[8], S41, 1873313359);  /* 57 */
    II(d, a, b, c, in[15], S42, 4264355552); /* 58 */
    II(c, d, a, b, in[6], S43, 2734768916);  /* 59 */
    II(b, c, d, a, in[13], S44, 1309151649); /* 60 */
    II(a, b, c, d, in[4], S41, 4149444226);  /* 61 */
    II(d, a, b, c, in[11], S42, 3174756917); /* 62 */
    II(c, d, a, b, in[2], S43, 718787259);   /* 63 */
    II(b, c, d, a, in[9], S44, 3951481745);  /* 64 */

    buf[0] += a;
    buf[1] += b;
    buf[2] += c;
    buf[3] += d;
}
EXTERN_ALIAS(md5_final);

/*
 **********************************************************************
 ** End of md5.c                                                     **
 ******************************* (cut) ********************************
 */
